# Homework Help: Automobile Centripetal acceleration

1. Sep 18, 2006

### bearhug

The cornering performance of an automobile is evaluated on a skidpad, where the maximum speed that a car can maintain around a circular path on a dry, flat surface is measured. Then the centripetal acceleration is calculated as a multiple of "g", the free-fall acceleration due to gravity at the earth's surface. The main factors affecting the performance are the tire and the suspension of the car. A Dodge Viper GTS can negotiate a skidpad of radius 58 m at 89 km/h. Calculate the centripetal acceleration due to static friction for this maneuver.

89km/h= 24.7m/s

Originally the first equation that pops into my head is a=v^2/r. However what's throwing me off is how the problem says that accerleration is a multiple of g (9.8). Then it also mentions to calculate the accleration due to static friction fs. Is the coefficient of static friction at all relevant to this problem? All the other equations I've looked at involve the coefficient which is also what's confusing me.

2. Sep 18, 2006

### Staff: Mentor

You have the right equation. To express the acceleration in terms of g, just divide your answer by 9.8 m/s^2. (Example: If the acceleration were 19.6 m/s^2, that would be 2 g's.)

Static friction is producing the centripetal force, but that's just background info. All you need to do is calculate the acceleration.

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